1. Field of the Invention
The present invention relates to a vehicle control device and to a diagnostic method therefor, and especially relates to a vehicle control device that is communicably connected to other control devices so that CAN (Controller Area Network) communication can be performed through a communication bus and a diagnostic method therefor.
2. Description of Related Art
It was known that, in a vehicle control device that uses CAN communication, the vehicle control device includes a main control means and a sub control means and stops a transmission output of control information from the main control means to other control devices through a CAN communication line when the sub control means detects an abnormality of the main control means (for example, refer to Japanese Patent Application Publication No. 2004-122942).
However, the above conventional vehicle control device is based on the assumption that its transmission stop function that stops the transmission output of the control information operates properly, and a case in which the transmission stop function has an abnormality is not considered. Therefore, a response may be delayed when an abnormality occurs in the transmission stop function. As a result, even when the transmission output of control information is tried to be stopped, there may be a risk that the control information is actually transmitted to other control devices.